S-98704A125 4-40 x 25/32" Thumb Screws

Key Features & Benefits at a Glance

• Tool-free manual operation with knurled acetal plastic head for secure grip and quick adjustments in tight spaces
• Corrosion-resistant 18-8 stainless steel construction ensures long-term reliability in humid or chemical environments
• Precision Class 3A thread fit provides superior engagement and vibration resistance in demanding applications
• Low-profile round head design minimizes protrusion while maintaining comfortable thumb pressure distribution
• Dual-material engineering combines stainless steel strength with plastic head's electrical insulation properties
• Full 25/32" threading offers maximum fastening depth and load distribution across the entire screw length
• Environmental compliance meets RoHS 3 and REACH standards for safe use in regulated industries

Professional Applications & Engineering Value

Engineered for industrial equipment maintenance and electronic enclosures, these 4-40 UNC thumb screws solve critical access challenges where frequent adjustments are required. The black acetal plastic knurled head provides excellent grip even with oily gloves, while the low-profile design prevents snagging in crowded panels. The 18-8 stainless steel body resists corrosion from coolants and atmospheric moisture, maintaining Class 3A thread precision through repeated cycles. This combination delivers reliable performance in test fixtures, instrumentation panels, and access covers where tool-less operation and corrosion resistance are paramount.

Specification Summary & Compliance

Manufactured to UNC coarse thread standards with Class 3A thread fit for precision applications. Features include 4-40 thread size, 25/32" fully threaded length, and 5/16" head diameter. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. The acetal plastic head operates within 32° to 180° F temperature range, suitable for most industrial environments.